Is there a program for msts they lets you make you make your own route?
The game comes with a route editor, which is where you can build your own routes. It is very tempremental and is full of quirks. Almost every single person who tries to build a route highly recommends buying the bible of rotue building: “A Guide to Route Building” by Michael Vone, published by Abacus. It comes as a downloadable 340+ page .pdf document, available for US $ 20.- at http://www.abacuspub.com/.
I have it and it is a step by step guide on how to build a route. It explains everything in a step by step method. You can either just read the parts on how to do stuff to build a route, which are in blue boxes, or you can read the how and why you do it that way in the rest of the book.
For the objects to use when route building, the best place to get them is the www.train-sim.com file library.
Richard Garber also has a bunch of buildings available on his site.